The major objective of this proposal is to generate a panel of monoclonal antibodies against tumor-specific antigens expressed on human melanoma cells. This will be accomplished by producing somatic cell hybrids (hybridomas) between drug marked mouse myelomas and splenic lymphocytes from mice immunized against human melanoma tissue. Clones of hybridomas will be isolated and the specificity of the antibodies which they produce will be determined by quantitative absorption with various normal and neoplastic tissues. This panel of monoclonal antibodies will allow for various aspects of the immunobiology of human malignant melanoma to be studied. Preliminary data has shown that circulating immune complexes are present in melanoma patients. One specific question concerning the immunobiology of human melanoma will be pursued in this proposal, i.e. the relationship between host immune response to melanoma and circulating immune complexes. It will be determined whether or not the same antigens (detected with monospecific antisera) which are present on melanoma tissue are associated with circulating immune complexes.